基于声波的结构健康诊断方法研究

A preliminary study on structural damage detection method based on sound wave

基于振动的损伤诊断方法,先后有动力参数诊断法、模型修正与系统识别法、神经网络法、小波分析和Hilbert变换法、遗传算法、布里渊散射光时域反射测量技术(BOTDR)以及对称信号法,但这些诊断方法都有一个共同的缺点,即所测结构模态参数对结构损伤程度的不敏感性.提出了基于声波的结构健康诊断方法,通过对磁盘边缘进行敲击,获得了损伤磁盘和无损伤磁盘的声音信号,对相应的声音信号进行处理,得到了其时程曲线和FFT谱;然后将损伤磁盘和无损伤磁盘的声音信号进行对比,发现损伤磁盘的信号与无损伤磁盘的信号有明显区别,以此可以判定结构损伤与否.

Up to the present, there have been many structural damage detection methods based on vibration. But there is a fatal weakness on these methods which is the difficulty to response the level of damage of structure by testing the dynamic parameters. In this paper, the method of structural damage detection based on sound wave is presented. By knocking the edge of plate, the sound signals of damaged plate and undamaged plate is got. The difference between the signals of damage plate and undamaged plate by comparing the time history and FFT spectrum of these signals is found. Whether the structure is damaged or undamaged can be judged according to the difference. This paper provides the basis for the following research.